Apparatus for heating fluids

Abstract: A system for the heating of fluids by causing severe turbulence of the fluid within a cavity of a housing (16). The device utilizes a rotor (12) closely received within a cavity, the rotor mounted upon a rotatable shaft (14), with the surface of the rotor (12) provided with a plurality of uniformly-spaced recesses (20) oriented at a selected angle to the surface. The shaft (14) is journalled in bearing assemblies (46,48) and seal units (50,52) at end walls (44) of the housing (16), and the shaft (14) is rotated by any suitable motive means (17). The heated fluid then is stored in any suitable storage facility, or utilized for any desired purpose. The system is specifically described for the purpose of heating water. This heated water is for standard use in a facility and, if desired, to provide heat input to air within that facility. Several embodiments of the conversion unit are given together with system elements to provide desired control of the heating of the water and of the facility. The preferred conversion unit has readily replaceable bearing assemblies.

Description: The present invention relates to a system for the heating of a fluid, said system comprising: a storage vessel for receiving heated fluid, said vessel having an inlet and an outlet; a mechanical conversion device for heating fluid, said conversion device having (a) a housing defining a cavity, said cavity formed by a cylindrical side wall and a pair of end plates, each of said end plates provided with centrally disposed openings, said end plates defining interior and exterior surfaces, (b) seal members mounted in said openings of said end plates, (c) a bearing assembly mounted on said exterior surface of said end plates and aligned with said openings, (d) a shaft passing through an axis of said cavity and journalled in said bearing assemblies and seal members, said shaft connected to motive means to rotate said shaft, (e) a rotor mounted on said shaft within said cavity so as to rotate with said shaft, said rotor dimensioned to be closely received within said side wall and said end plates, (f) an inlet port for the introduction of fluid to be heated into said space between said rotor and said inner surface of said cavity, and (g) an outlet port for the removal of heated fluid from said space between said rotor and said inner surface of said cavity; a first fluid connection connected to said inlet port of said conversion device for introduction of fluid to be heated into said conversion device; and a second fluid connection connected between said outlet port of said conversion device and said input of said storage vessel. Such a system is known from US-A-4 277 020. The heat is generated by internal friction and agitation. During operation, the rotor generates forces parallel to the longitudinal extension of the shaft. Therefore, bearings compensating axial forces are required. Various other designs exist for devices which use rotors or other rotating members to increase pressure and/or temperature of fluids. These include devices useful where it is desired to convert fluids from the liquid to gaseous phases. U.S. patent 3,791,349 issued to Scharfer on February 12, 1974, for instance, discloses an apparatus and method for the production of steam and pressure by the intentional creation of shock waves in a distended body of water. Various passageways and chambers are employed to create a tortuous path for the fluid and to maximize the water hammer effect for the heating/pressurization. Other devices which employ rotating members to heat fluids are disclosed in U.S. patent 3,720,372 issued to Jacobs on March 13, 1973, which discloses a turbine-type coolant pump driven by an automobile engine to warm engine coolant; U.S. patent 2,991,764 issued July 11, 1961, which discloses a fluid agitation type heater; and U.S. patent 1,758,207 issued to Walker on May 13, 1930, which discloses a hydraulic heat generating system that includes a heat generator formed of a vaned rotor and stator acting in concert to heat fluids as they move relative to one another. These devices employ structurally complex rotors and stators which include vanes or passages for fluid flow, thus resulting in structural complexity, increased manufacturing costs, and increased likelihood of structural failure and consequent higher maintenance costs and reduced reliability. Still other references that may be pertinent to an evaluation of the present invention are U. S. Patent Numbers: 2,316,522 issued to J. E. Loeffler on April 13, 1943; 3,508,402 issued to V. H. Gray on April 28, 1970; 3,690,302 issued to P. J. Rennolds on September 12, 1972; 4,381,762 issued to A. E. Ernst on May 3, 1983; and 4,779,575 issued to E. W. Perkins on October 25, 1988. It is accordingly an object of the present invention to provide a device for heating fluid in a void located between a rotating rotor and stationary housing, which device is structurally simple and requires reduced manufacturing and maintenance costs. Another object of the present invention to produce a mechanically elegant and thermodynamically highly efficient means for increasing pressure and/or temperature of fluids such as water (including, where desired, converting fluid from liquid to gas phase). It is an additional object of the present invention to provide a system for providing heat and hot water to residences and commercial space using devices featuring mechanically driven rotors for heating water. A further object of the present invention is to provide a system for heating fluids, and particularly water, for providing heat to facilities wherein the mechanical rotating heating device is constructed for easy manufacture and ready replacement of components. Other objects, features and advantages of the present invention will become apparent upon consideration of the drawings set forth below together with reference to the detailed description thereof in this document. The objects are achieved according to the invention by a system for the heating of a fluid of the aforementioned kind wherein said rotor having a surface toward said side wall provided with bores at a selected angle to said surface, said bores producing turbulence of fluid within a space between said rotor and an inner surface of said cavity and said bearing assembly being releasably mounted. Brief Description of the Drawings Figure 1 is a partially cutaway perspective view of a first embodiment of a device according to the present invention. Figure 2 is a cross-sectional view of a second embodiment of a device according to the present invention. Figure 3 is a cross-sectional view of a device according to a third embodiment of the present invention. Figure 4 is a schematic view of a residential heating system according to the present invention. Figure 5 is a partial cross-sectional view of a further embodiment of a bearing/seal arrangement for a device of the type illustrated in Figures 1 and 2. Figure 6 is a partial cross-sectional view of a further embodiment of a bearing/seal arrangement for a device of the type illustrated in Figure 3. Best Mode for Carrying out the Invention As shown in Figure 1, the device 10 in briefest terms includes a rotor 12 mounted on a shaft 14 , which rotor 12 and shaft 14 rotate within a housing 16 . Shaft 14 in the embodiment shown in Figures 1 and 2 typically has a primary diameter of 45 mm (1 3/4'') and may be formed of forged steel, cast or ductile iron, or other suitable shaft materials as desired. Shaft 14 may be driven by an electric motor 17 or other motive means, and may be driven directly (as shown) or with gears, driven by pulley, or driven as otherwise desired. The rotor 12 is fixedly attached to the shaft 14 , and typically may be formed of aluminum, steel, iron or other metal or alloy as appropriate. Rotor 12 is essentially a solid cylinder of material featuring a shaft bore 18 to receive shaft 14 , and a number of irregularities 20 are formed in its cylindrical surface. In the embodiment shown in Figures 1 and 2, the rotor 12 is typically 152 mm (six inches) in diameter and 229 mm (nine inches) in length, while in the embodiment shown in Figure 3 the rotor 12 is typically 254 mm (ten inches) in diameter and 102 mm (four inches) in length. Locking pins, set screws or other fasteners 22 may be used to fix rotor 12 with respect to shaft 14 . In the embodiment shown in Figure 1, the rotor 12 features a plurality of regularly spaced and aligned bores 24 drilled, bored, or otherwise formed in its cylindrical surface 26 . Bores 24 may feature countersunk bottoms, as shown in Figure 2. Bores 24 may also be offset from the radial direction either in a direction to face toward or away from the direction of rotation of rotor 12 . In one embodiment of the invention, the bores 24 are offset about fifteen degrees from the radial in the direction of rotation of rotor 12 . Each bore 24 may feature a lip 25 where it meets surface 26 of rotor 12 , and the lip may be flared or otherwise contoured to form a continuous surface between the surfaces of bores 24 and cylindrical surface 26 of rotor 12 . Such flared surfaces are useful for providing areas in which vacuum may be developed as rotor 12 rotates with respect to housing 16 . The depth, diameter and orientation of bores 24 may be adjusted in dimension to optimize efficiency and effectiveness of device 10 for heating various fluids, and to optimize operation, efficiency, and effectiveness of device 10 with respect to particular fluid temperatures, pressures and flow rates, as they relate to rotational speed of rotor 12 . In a preferred embodiment of the device, the bores 24 are formed radially at about eighteen degrees apart from one another and have a depth greater than their diameter. In the embodiment shown in Figures 1 and 2, housing 16 is formed of two housing bells 30A and 30B which are generally C-shaped in cross section and whose interior surfaces 32A and 32B conform closely to the cylindrical surface 26 and ends 34 of rotor 12 . The device shown in Figures 1 and 2 feature a 2,5 mm (0.1 inch) clearance 28 between rotor 12 and housing 16 in both the radial direction and the axial direction. Smaller or larger clearances may obviously be provided, once again depending upon the parameters of the fluid involved, the desired flow rate and the rotational speed of rotor 12 . Housing bells 30A and 30B may be formed of aluminum, stainless steel or otherwise as desired, and preferably feature a plurality of axially disposed holes 36 through which bolts or other fasteners 38 connect housing bells 30A and 30B in sealing relationship. Each housing bell 30A and 30B also features an axial bore 40 in an end wall 39 sufficient in diameter to accommodate the shaft 14 together with seals about the shaft, and additionally to permit flow of fluid between the shaft, seals, and housing bell 30A and 30B and bores 40A and 40B . The interior surface 32A and 32B of housing bells 30A and 30B may be smooth, as shown, with no irregularities, or may be serrated, feature holes or bores or other irregularities as desired to increase efficiency and effectiveness of device 10 for particular fluids, flow rates and rotor 12 rotational speeds. In the preferred embodiment, there are no such irregularities. Connected to an outer surface 44A and 44B of the end wall 39 each housing bell 30A and 30B is a bearing plate 46A and 46B . The primary function of bearing plates 46A and 46B is to carry one or more bearings 48A and 48B (roller, ball, or as otherwise desired) which in turn carry shaft 14 , and to carry an 0-ring 50A and 50B that contacts in sliding relationship a mechanical seal 52A and 52B attached to shaft 14 . The seals 52A and 52B acting in combination with the 0-rings 50A and 50B prevent or minimize leakage of fluid adjacent to shaft 14 from the device 10 . Mechanical seals 52A and 52B are preferably spring-loaded seals, the springs 53A , 53B biasing a gland 54A and 54B against 0-ring 50A and 50B formed preferably of tungsten carbide. Obviously, other seals and O-rings may be used as desired. One or more bearings 48A and 48B may be used with each bearing plate 46A and 46B to carry shaft 14 . Bearing plates 46A and 46B may be fastened to housing bells 30A and 30B using bolts 58 or other fasteners as otherwise desired. Preferably disk-shaped retainer plates 60 through which shaft 14 extends may be abutted against end plates 46A and 46B to retain bearings 48A and 48B in place. In the embodiment shown in Figures 1 and 2, a fluid inlet port 63 is drilled or otherwise formed in each bearing plate 46A and 46B (Figure 1) or in end wall 44A of housing 16 (Figure 2), and allows fluid to be heated to enter device 10 first by entering a chamber or void 64 hollowed within the bearing plate 46A or 46B (Figure 1), or directly into the clearance space 28 located between rotor 12 and housing 16 (Figure 2). Fluid which enters through a bearing plate 46 then flows from the chamber 64 through the axial bore 40A and 40B in housing bell 30A and 30B as rotor 12 rotates within housing 16 . The fluid is drawn into the clearaiice space 28 between rotor 12 and housing 16 , where rotation of rotor 12 with respect to interior surface 32A and 32B of housing bells 30A and 30B imparts heat to the fluid. One or more exhaust ports or bores 66 are formed within one or more of housing bells 30A and 30B for exhaust of fluid at higher pressure and/or temperature. Exhaust ports 66 may be oriented radially (as shown in Figure 1) or as otherwise desired, and their diameter may be optimized to accommodate various fluids, and particular fluids at various input parameters, flow rates and rotor 12 rotational speeds. Similarly, inlet ports 63 may penetrate bearing plates 46A and 46B or housing 16 in an axial direction, or otherwise be oriented and sized as desired to accommodate various fluids and particular fluids at various input parameters, flow rates and rotor 12 rotational speeds. The device shown in Figures 1 and 2, which uses a smaller rotor 12 , operates at a higher rotational velocity (on the order of 5000 rpm) than devices 10 with larger rotors 12 . Such higher rotational speed involves use of drive pulleys or gears, and thus increased mechanical complexity and lower reliability. Available motors typically operate efficiently in a range of approximately 3450 rpm, which the inventor has found is a comfortable rotational velocity for rotors in the 185 mm to 254 mm (7.3 to ten inch) diameter range. Devices as shown in Figures 1-3 may be comfortably driven using 3,7 to 5,6 kW (5 to 7.5 horsepower) electric motors. The device shown in Figures 1 and 2 has been operated with 13 mm (1/2 inch) pipe at 5000 rpm using city water pressure at approximately 5,2 bar (75 pounds). Exit temperature at that pressure, with a comfortable flow rate, is approximately 150°C (300° F). The device shown in Figures 1 and 2 was controlled using a valve at the inlet port 63 and a valve at the exhaust port 66 and by adjusting flow rate of water into the device 10 . Preferably, the valve at the inlet port 63 is set as desired, and the exhaust water temperature is increased by constricting the orifice of the valve at the exhaust port 66 and vice versa. Exhaust pressure is preferably maintained below inlet pressure; otherwise, flow degrades and the rotor 12 simply spins at increased speeds as flow of water in void 28 apparently becomes nearer to laminar. Figure 3 shows another embodiment of a device 10' according to the present invention. In this figure elements that are the same as in Figures 1 and 2 carry the same identifying numerals, and elements that are slightly changed but serve the same functions carry primed numerals. This device features a rotor 12' having larger diameter and smaller length, and being included in a housing 16' which features only one housing bell 30' . The interior surface 32 ' of housing bell 30 ' extends the length of rotor 12 '. A housing plate 68 , preferably disk shaped and of diameter similar to the diameter of the housing bell 30 ', is connected to housing bell 30 ' in a sealing relationship to form the remaining wall of housing 16 '. Housing plate 68 , as does housing bell 30 ', features an axial bore 40 sufficient in diameter to accommodate shaft 14 , seals 52A and 52B and flow of fluid between voids 64 formed in bearing plates 46A and 46B . This embodiment accommodates reduced fluid flow and is preferred for applications such as residential heating. The inlet port 63 of this device is preferably through housing 16 ', as is the exhaust port 66 (through housing plate 68 ), but may be through bearing plates 46 as well. The device 10 ' shown in Figure 3 is preferably operated with 19 mm (3/4 inch) copper or galvanized pipe and rotation at approximately 3450 rpm, but may be operated at any other desired speed. At an inlet pressure of approximately 4,5 bar (65 pounds) and exhaust pressure of approximately 3.5 bar (50 pounds), the outlet temperature is in the range of approximately 150°C (300° F). Figure 4 shows a residential heating system 70 according to the present invention. The inlet side of device 10 (or 10 ') is connected to a hot water line 71 of a (deactivated) hot water heater 72 . The exhaust of device 10 is connected to exhaust line 73 which in turn is connected to the furnace or HVAC heat exchanger 74 and a return line 76 to cold water supply line 77 of hot water heater 72 . The device 10 according to one embodiment of such a system features a rotor 12 having a diameter of 8 inches. A heat exchanger inlet solenoid valve 80 controls flow of water from the device 10 to heat exchanger 74 , while a heat exchanger exhaust solenoid valve 82 controls flow of water from heat exchanger 74 to return line 76 . A third solenoid valve in the form of a heat exchanger by-pass solenoid valve 84 , when open, allows water to flow directly from device 10 to return line 76 , bypassing heat exchanger 74 . Heat exchanger valves 80 and 82 may be connected to the normally closed side of a ten ampere or other appropriate relay 78 , and the by-pass valve 84 is connected to the normally open side of the relay 78 . The relay 78 is then connected to the air conditioning side of the home heating thermostat, so that the by-pass valve 84 is open and the heat exchanger valves 80 and 82 are closed when the home owner enables the air conditioning and turns off the heat. A contactor 86 is connected to the thermostat in the hot water heater and the home heating thermostat so that actuation of either thermostat enables contactor 86 to actuate the motor driving device 10 . (In gas water heaters, the temperature switch may be included in the line to replace the normal thermocouple.) The hot water heater 72 is turned off and used as a reservoir in this system of Figure 4 to contain water heated by device 10 . The device 10 is operated to heat the water to approximately 82°C-88°C (180 - 190° F), so that water returning to hot water heater 72 reservoir directly via return line 76 is at approximately that temperature, while water returning via heat exchanger 74 , which experiences approximately a 40° temperature loss, returns to the reservoir at approximately 65°C (150° F). Cutoff valves 88 allow the device 10 and heat exchanger 74 to be isolated when desired for maintenance and repair. One of the problems encountered with devices of the types illustrated in Figures 1-3 is that related to heat damage to seals and bearings after extensive operation. In order to reduce the problem, certain modifications have been made as illustrated in Figures 5 and 6. In Figure 5, for example, the end walls (end plates) 90 of a fluid heating device 92 are increased in thickness. Then by using a bearing assembly 94 attached thereto as with bolts 96 that are threadably received in the end wall 90 at 97 , the bearing 98 within this assembly 94 is farther removed from the interior 100 of the device 92 . When any damage occurs to the bearing 98 , or any seals (not shown) of the bearing 98 , the entire bearing assembly 94 can be removed and replaced with a new assembly. This can be contrasted with the more complex structure of Figure 2. It will be understood that the device 92 has an opposite end wall or plate (not shown) of substantially the same construction. This end wall 90 utilizes the same spring-loaded seal arrangement 102 as illustrated in Figures 2 and 3. In this embodiment the housing of the device 92 is completed with a cylindrical wall 104 that is held to the two end walls 90 with bolts 106 passing through apertures 108 in the end walls 90 . It will be noted that ends of this cylindrical wall 104 are received in recesses 110 in the end wall 90 , and sealing is provided with an O-ring 112 or the equivalent type of seal. In this embodiment the inlet for the device 92 is through a threaded port 114 in the end wall 90 (the outlet can be in an opposite end wall). Both this inlet as well as the outlet can be, of course, in other locations as suggested with regard to Figures 2 and 3. In this embodiment the rotor is shown at 116 as mounted on the shaft 118 . This rotor 116 can be of the types previously discussed with regard to Figures 2 and 3, and will include regularly-spaced recesses in its surface to create turbulence. The embodiments of Figures 5 and 6 can be utilized in the system illustrated in Figure 4, or in other systems for the heating of fluids in a system.

Claims: A system for the heating of a fluid, said system comprising: a storage vessel (72) for receiving heated fluid, said vessel having an inlet and an outlet; a mechanical conversion device (10) for heating fluid, said conversion device having (a) a housing (16) defining a cavity, said cavity formed by a cylindrical side wall (32A, 32B) and a pair of end plates (39A, 39B), each of said end plates provided with centrally disposed openings (40A, 40B), said end plates defining interior and exterior surfaces (44A, 44B), (b) seal members (52A, 52B) mounted in said openings of said end plates, (c) a bearing assembly (46A, 46B, 48A, 48B) mounted on said exterior surface of said end plates and aligned with said openings, (d) a shaft (14) passing through an axis of said cavity and journalled in said bearing assemblies and seal members, said shaft connected to motive means (17) to rotate said shaft, (e) a rotor (12) mounted on said shaft within said cavity so as to rotate with said shaft, said rotor dimensioned to be closely received within said side wall and said end plates, (f) an inlet port (63) for the introduction of fluid to be heated into said space between said rotor and said inner surface of said cavity, and (g) an outlet port (66) for the removal of heated fluid from said space between said rotor and said inner surface of said cavity; a first fluid connection (71) connected to said inlet port of said conversion device for introduction of fluid to be heated into said conversion device; and a second fluid connection (73) connected between said outlet port of said conversion device and said input of said storage vessel, characterised by said rotor having a surface toward said side wall provided with bores (24) at a selected angle to said surface, said bores producing turbulence of fluid within a space between said rotor and an inner surface of said cavity and said bearing assembly (46A, 46B, 48A, 48B) being releasably mounted. The system of claim 1 further comprising a heat exchanger (74) for transferring heat of fluid within said storage vessel to another fluid, said heat exchanger having an inlet connected to said outlet of said storage vessel and an outlet connected to said inlet of said storage vessel. The system according to claim 2 further comprising a first fluid transport line (76) between said outlet of said heat exchanger and said inlet port of said conversion device. The system according to one of claims 2 or 3 further comprising: a second fluid transport conduit (73) between said outlet port of said conversion device and said inlet of said heat exchanger; and a valve unit (84) to selectively connect said outlet of said storage vessel with said inlet of said heat exchanger and said outlet of said conversion device with said inlet of said heat exchanger. The system according to one of claims 2 to 4 further comprising: a regulating valve (88) in said fluid connection to said inlet port of said conversion device for regulating rate of flow into said conversion device; and a second regulating valve (80) in said fluid connection to said outlet port of said conversion device for regulating rate of flow out of said conversion device to control heating of said fluid by said conversion device, said second regulating valve providing for an exhaust pressure of a value less than inlet pressure. The system according to one of claims 2 to 5, wherein the fluid heated by said conversion device is water and wherein the heat of the water is transferred to air by the heat exchanger. The system according to one of claims 2 to 6 further comprising a thermostatically controlled valve (84) in said fluid connection to said inlet to said heat exchanger whereby flow of heated water into said heat exchanger is controlled depending upon a thermostat within said system whereby heating of air within said system is controlled. The system according to one of claims 2 to 7 further comprising a bypass valve (84) connected between said inlet and said outlet of said heat exchanger to selectively bypass flow of heated water around said heat exchanger when heating of air by said heat exchanger is not desired. The system according to one of claims 1 to 8 further comprising auxiliary heating means positioned within said storage vessel to provide additional heat to water within said storage vessel. The system according to one of claims 1 to 9 further comprising a control system connected to said motive means connected to said shaft, said control system energising and de-energising said motive means upon a signal from a sensor within said storage vessel, said signal related to temperature of water within said storage vessel. The system according to claim 10, wherein said control system energises and de-energises said motive means upon a second signal from a sensor within said system, said second signal related to temperature of air within said system.

Inventors: GRIGGS JAMES L, GRIGGS, JAMES L.
Applicants: HYDRO DYNAMICS INC, HYDRO DYNAMICS, INC.
Application year: 1994
Main classification: F24J3
IPC codes: F24J3, F24H1, F24H3, B01F7